If it sounds like a pretty high number, you're right. Last year, the Super Bowl betting figure was estimated to be $4.76 billion.

Not all of that money will be bet legally.

But experts say increased interest in gambling on this year's matchup might've been triggered by legalization of certain sports betting across the U.S.

In May, a Supreme Court ruling struck down a federal law that effectively banned sports gambling, leaving it up to states to decide whether to legalize it or not. Now, regulated sports betting is being offered in eight states, with more likely in the works.